1. Field of Use
The present invention relates to V-type, two-cylinder, internal combustion engines for motorcycles in which the spark plugs for the cylinders are mounted adjacent the rocker boxes and parallel to the longitudinal axis of each cylinder. The invention pertains to a means for positioning the ignition coils of such engines adjacent to the spark plugs.
2. Prior Art
V-type two-cylinder motorcycle engines are well known to those of ordinary skill in the art. Typical of such engines are described in U.S. Pat. No. 4,558,676 to Seidl, and U.S. Pat. No. 6,729,294 to Okano, et al. In such V-type engines there is typically a coil for each cylinder mounted adjacent the battery and/or the generator of the motorcycle, or other location on the frame of the motorcycle. In other V-type engines there is only one coil for controlling both spark plugs. An ignition coil (also called a spark coil) is an electrical device in a motorcycle's ignition system that transforms a storage battery's 12 volts to the thousands of volts needed to spark the spark plugs. This ignition coil is a specific form of the induction coil that converts current from a battery into the high voltage current required by spark plugs in an internal combustion engine. The output of each coil is electrically connected to the terminal, or cap of the spark plug by means of a wire extending from the coil to the spark plug. As shown in FIG. 1, the spark plug wires are typically run external to the motorcycle engine. Since insulated spark plug wires are more expensive than regular electrical wire, it would be economically beneficial to devise a structure that enables the reduction in the length of the spark plug wires. One of ordinary skill in the art would know that the insulation portion of spark plugs are typically made of ceramic, and somewhat brittle. Thus, the exposed spark plug is subject to damage if there are any physical problems with the motorcycle. Such as crashes or collisions. It would also be beneficial to devise a structure that would provide a barrier to such physical damage.
The present invention overcomes both these disadvantages and provides a solution to both the economics of the insulated spark plug wires and protects the spark plugs from physical damage.